Some side-effects noted by e-smokers: Weight gain, notably, wallet has more money in it and weighs you down. Smoking indoors increased, irreparably harming people nearby with nontoxic vapor. Increased USB power consumption. Feelings of fraud/enlightenment when smoking near people using actual cigarettes. Ability to run without wheezing. If wallet gets too heavy to carry consult your doctor or accountant.

all kidding aside there are some side effects and they are dependant on the user